Ingot-mold.



E. GATHMANN,

B Q\\\W I v B g wuowto'a Emil GaZhmaJm ZZZ UNITED STATES PATENT OFFICE.

EMIL GATHMANN, OF BALTIMORE, MARYLAND.

INGOT-MOLD.

Specification of Letters Patent. Patented NOV. 13, 1917.

Original application filed February 27, 1913, Serial No. 751,006. Divided and this application filed June 80,

1913. Serial No. 778,544.

To all whom it may concern:

Be it known that I, EMIL GATHMANN, a citizen of the United States, residing in Baltimore city and State of Maryland, have invented certain new and useful Improvements in Ing0t-Molds,-of which the following is a specification.

The application for this patent is a 'di vision of my application for Patent No. 751,006 filed February 27, 1913, the claims in said application being confined to the ingot.

*- This invention relates to the manufacture of ingots which shrink during solidification and particularly to the manufacture of ingots of crucible or high gradesteel or alloys.

'It hasbeen found by numerous experiments that when the mold cavity is larger at its upper than at its lower end and gradually tapers toward the lower end where the cross section is smaller, the lower portion of the ingot freezes or solidifies more quickly as less heat units are contained therein than in the larger portion of the ingot. This taperin of the ingot should be progressive ibut uni orm, i. e., there should not be any sudden change in taper as that might cause r'tlle ingot to hang at some point of the mold.

- With the ordinary tapered ingot for crucible Jsteel practice, tapered suflicien'tly to ma- 'able difierence in area teriallv rP-duce the depth of pi e, consideretween t e upper and lower part of the ingot is necessary Furthermore dilliculty has been encountered in stacking: and piling ingots for storage on account of their varying dimensions from end to end, and it has also been found somewhat difiicult to work such ingots under the steam hammer 'or hydraulic press. Notwithstanding these objections such ingots i have been and are now very extensively used.

improved mold it is essential that there be :onsiderable lag in the cooling of the u'pper )ortion thereof compared with the time of reezing of the lower portion, hence the least listance from the vertical central axis of the ngo't to the side walls thereof is made much less at the bottom of the ingot than a any other point and this distance progressively increases toward the top of the ingot. 'Inp1pe does not truly indicate the actual vollune or weight of cropping necessary to obtain physically sound steel.

By my improvements I produce tapered ingots with less difference in the upper and lower cross sectional area than would ordi- Ilallly be the practice to obtain like results, and such ingots may be readily and unifomly stacked and worked under the hammer and press and which, where the steel or alloy--has been disgasified by suitable previous treatment, are practically free from pipge or blow-holes.

y my improvements also I obtain practically uniform section of the ingot in certain longitudinal planes, but a decreased section from the top toward the bottom of the ingot with consequent change of dimensions in other longitudinal sections. This I do by so forming the mold cavity as to leave. some of the sides of-the ingot practically straight and parallel, while others are considerably tapered or are tapered relatively to the other sides, or given a more pronounced taper than the other-sides. Although the freezing or mode of solidification of the liquid steel or alloy, which shrinks or contracts during such coolin and solidification, depends to a considerab e extent u on the cross sectional area of the in ot, it e ends more particularly upon the east thic of the ingot at various horizontal planes thereof and also upon the relative heat absorptive power of the walls of the mold in various horizontal planes.

In the accompanying drawings,

Figure 1 shows a vertical central section through an ingot mold embodying provements.

Fig. 2 shows a top plan view thereof..

Fig. 3' shows a section .on the line 3-3 of Fig.

Fig. 4 shows a side elevation of one section of the mold.

The mold shown in the drawings is a sectional mold being divided vertically or lon- I gitudinally. This is the preferred form although not essential as various constructions of mold may be used to produce the desired ingots which are not made in section. Where not made in sections the mold cavity should be tapered on allsides to such an extent as to permit the .easy withdrawal of the ingot, but two of the sides should be tapered to a greater extent as will be hereinafter described. The walls of the mold are made relatively" thick in the lower portion thereof at B and relatively thin at the upper or neck portion B, as by such construction the lower portion of the mold absorbs heat rapidly from the ingot, While the thin portion or neck is less absorptive. In this way the pipe which ordinarily forms in the process of manufacture is forced to the top where it disa pears or dwells near the upper portion o the ingot leaving a relativel small end and area to be cropped. When tlie mold is made in sections, as shown, suitable devices are employed for securing them together. 1

When an ingot is being cast in a mold such as shown heat will radiate rapidly to the thick walls of the mold where it willbe 'quickly absorbed, while the wider portion at the top'of the ingot will cool more slowly and the thin walls B being less absorbent the'walls B on opposite sides of the smaller diameter of the mold cavity are of sub stantially the same thicknex and are thicker than the walls B.

I claim as my invention v 1. A mold having a cavity which is of substantially square horizontal cross sectionat its upper portion and substantially ob long in horizontal cross section at its lower portion.

2. A mold having a cavity which is of substantially square horizontal cross section at its upper portion and substantially ob long in horizontal cross-section at its lower portion, the mold walls on the opposite sides of the smaller diameter of the cavity being thicker than the remaining or intervening walls.

In testimo y whereof, I have hereunto subscribed my name. i

' EMIL GATHMANN.

Witnesses: Y V

FRANK B. Sm, W D. POULTNEY. 

